The field of the invention pertains to grinding wheels. In particular, the invention pertains to a device for dressing or shaping the grinding wheel for sharpening and imparting a certain shape to the blade of an ice skate. In the past, dressing the wheel was inexact and hence the shape given to an ice skate blade was variable. The dressing devices were not stabilized enough to keep the dressing tool in a consistent relation with the grinding wheel. Another disadvantage was that the placement of the dressing tool to the grinding wheel was difficult as the dressing tool was not easily movable.
By dressing the grinding wheel, a certain shape is imparted to the wheel, which shape then is imparted to the ice skate blade as the blade is sharpened by the wheel. Skates for certain purposes require certain shapes. A hockey player needs a hollow or a radius to be ground on the blade of the ice skate. The hollow grind creates two edges on the outside of the blade by lowering the center portion beneath the edges. A goalie on the other hand needs an almost flat blade with minimum of hollow provided to the skate. As skates are ground, the grinding wheel loses its shape, necessitating dressing of the wheel. Or when a different shape is needed, the grinding wheel must be dressed to the desired shape for the wheel to be able to impart the desired shape to the ice skate blade.
It is important the deepest part of the hollow be centered on the ice skate blade. If the deepest part of the hollow is too far to one side of the blade, the skater will be forced off balance thus affecting the skater""s performance.
A grinding wheel is partially contained within a housing that has a top cover or plate, a bottom, a back and sides. The invention includes a slide mechanism or rail assembly to move a dresser arm with dresser tool into and away from a grinding wheel. The grinding wheel is rotated horizontally for grinding, in this case, an ice skate blade. The dresser arm is moved in a horizontal direction along a rail assembly having a rail on each side of the housing.
The dresser arm is attached to ends of two rails and the dresser arm pivots around the attachment point of the rails. The dresser arm is slid via movable frame assembly/rails to place the dresser arm/dresser tool near the circumferential edge of the grinding wheel for the dressing operation.
The dresser arm with tool is moved in an arc for the dressing of the grinding wheel. The dresser arm is moved into engagement with the grinding wheel by pulling or pushing the dresser to move along the rails of the movable frame assembly. The movable frame assembly uses a rail on either side of the housing and a cross bar at the back of the housing. As discussed above, the dresser arm connects between the ends of the rails.
The movable frame assembly is positioned along the sides of a housing that partially encases the grinding wheel; leaving a portion of the wheel exposed. The exposed portion of the wheel is the location at which grinding occurs and the exposed portion of the wheel is also the location where dressing of the wheel occurs.
The movable frame assembly generally has two rails, one on each side of the housing. The rails are connected at the front by the dresser arm and at the back by a crossbar.
Bearings support the rails and the bearings being of a lubricating material, lubricate the movement of the rails. Both fixed and resilient bearings are used herein. Fixed bearings are disposed in a horizontal orientation and a vertical orientation. Fixed horizontal bearings are under each of the rails. The horizontal bearings are positioned perpendicularly to the sides and also to the rails. The bottom of the housing that holds the horizontal bearings extends to the outside of the side wall with the bearings placed therein with the horizontal bearings extending into the housing past the side wall of the housing.
Vertical bearings are placed and retained within partially circular cutouts in the side walls. The vertical bearings extend higher and lower than the rails and space the rails from the side walls, preventing binding of the rails with the side walls of the housing.
Resilient bearings or detents are used to hold the rails in position on the fixed horizontal bearing under the rails. The resilient bearings press against the rails from the top of the rails. The resilient bearings are held in a block above the rail with the block being attachable to the side wall of the housing. Alternately, the resilient bearings are held by the top plate of the housing with the top plate being extended beyond the side walls and over the rails of the rail assembly.
The rails can be shafts or bars. A bar having a square cross section can be used. A concavity can be formed into the rail to allow any grinding dust or other foreign materials to drop away from the rail. The resilient detents can be added to the rail itself to work against a top surface to force the rail against the fixed horizontal bearing under the rail.
The present invention is a device for moving a dressing (dresser) arm for the dressing of a grinding wheel for the purpose of preparing a grinding wheel for sharpening of an ice skate blade. The device locates and stabilizes the dressing tool for the dressing of the wheel and hence results in the sharpening of the ice skate blade with the desired shape. The device easily is moved into working position without binding.
Essentially, the invention comprises a housing almost completely surrounding the grinding wheel. The housing has a planar plate with sides and a back rising from the plate. A top plate fits to the housing almost encasing the grinding wheel. A segment of the wheel remains exposed for the actual dressing or sharpening. The housing protects the grinding wheel itself and also provides mass to dampen the vibration during the dressing of the wheel and during the sharpening process. The housing also provides some protection to the operator by containing the pieces of the grinding wheel in case the grinding wheel should break apart.
The grinding wheel is mounted on an end of a drive shaft that terminates inside the housing at the grinding wheel. The drive shaft is powered conventionally by a drive motor. A sliding mechanism is movable along the sides of the housing. At the front of the sliding mechanism, the dresser arm is designed to swing into place to position the dressing tool to the grinding wheel.
After the dresser arm swings the dressing tool in front of the grinding wheel, the dressing tool is introduced to the grinding wheel by moving the sliding mechanism so that the grinding tool engages with the grinding wheel. The dresser arm has an adjustment to allow the dresser tool to be placed against the desired point on the edge of the wheel. The adjustment is by an eccentric adjustment wheel at both ends of the dresser arm.
The movable frame comprises rails and/or shafts that slide on bosses on the sides of the housing. Bearings on the bosses and the housing facilitate the movement of the shafts. The rails/shafts connected at the front by the dresser arm and at the back by a cross bar. Blocks are affixed to the housing above the shafts to hold the shafts. Fixed and/or resilient bearings are added to the rails/shafts and to the blocks to allow the movable frame to easily slide into position. The bearings in the rails/shaft can be strip bearings that are placed into longitudinal grooves milled in the shafts. Resilient bearings or detents are also useful to provide resilient holding.
The rails/shafts must be maintained parallel with each other. Holding the rails/shafts apart or spacing the rails/shafts prevents binding of the movable frame. This is accomplished by attaching the ends of the rails/shafts within the yokes or split ends of the dresser arm. The mass of the dresser arm prevents the shafts from narrowing together and binding. The cross bar also is used for adjustably spacing the rails/shafts.
An alternate rails/shaft spreading device is a spacer connected above the housing. The spacer device comprises two bars that each have a vertical part that is joined to the rails/shaft. Each bar angles to a horizontal part over the top of the housing. The ends of the horizontal parts are threaded, one with right hand threads and the other with left hand threads. A connector having reverse threads, that is, one end having left hand thread and the other end having right hand threads, (similar to a turn buckle) is joined to the bars. Adjustment is made by turning the connector to space the rails/shafts apart or closer together. Lock screws secure the bars at the optimum spacing.
It is envisioned that the device can be advantageously employed with a variety of grinding devices, not just for skate grinding devices. An advantage of this device is the dresser tool is easily slid into position. This invention can be used on other types of grinder/sharpeners.
For a more complete understanding of the present invention, reference is made to the following detailed description when read with in conjunction with the accompanying drawings wherein like reference characters refer to like elements throughout the several views, in which: